Boom hoist



Sept. 5, 1944. B. s. FERGUSON 300M HOISI Filed Sept. 16, 1941 2Sheets-Sheet 1 m .m 0 Tm W% in a w L Arron/vs:

p 1944. B. s. FERGUSON 2,357,462

BOOM HOIST Filed Sept. 16, 1941 2 Sheets-Sheet 2 /NVENTOR: BER IN S.FERGUSON ATTORNEY Patented -Sept. 5,1944 I i 2 ,357,462 BOOM nors'rBerlin S. Ferguson, Bavenna, Ohio, assignor to Byers Machine Company,RaVennafOhio, a corporation of Ohio Application September-16, 1941,Serial No. 411,005 7 Claims; (01. 254187) UNITED STATES PATENT orrlcs 4In material-handling equipment of the type and such location does notrequire any additional to which power shovels belong the main boomgearing. is generally riggedfor raising and lowering by These and otheradvantages will be apparent a compound line running over a series ofsheaves to those skilled in the art from the description and wound upononeof the smaller drums of 5 and illustrations which accompany thedescripthe, mechanism. Such machinery includes shovtion.

els, drag-line scrapers, certain sorts of cranes, It will be understoodthat I have shown and and like mechanism. Often the working ar- Idescribed herein a preferred form of the invenrangements areinterchangeable, so that one tion, but that the principles thereof y b emachine can be used for all the purposes named P y With fi e w detailbychanging the attachments. One characterisn t e a o p ny dr w s:

tic of such machines is that the power plant Fig. 1 is a central axialvertical section of the and operative gearin must be placed in a smallmechanism, certain pa s bein S ow n elev space, and that there must beseveral drums tion; transverse to the assembly so that the numerous 2 isa transverse Section indicated by line cables can be led as directly aspossible. This -2 of Fig. 1, lookin in t e direct on 0f the need givesrise to the further requirement that arrows; and e the principal shaftbe transversely disposed, Fig. 3 is an end elevation indicated by theand that such shafts carry more than one drum. line 33 of Fig. 1,looking in the direction of The wear on all parts of the mechanism isthe arrows.

severe, which gives rise to the need of adequate The entire mechanism iscarried upo Shaft areas for wearing parts in spite of the strict llmounted in appropriate bearings l2, l3 at its limitations of space. Thisalso makes it necesopp s e ds. this shaft bein preferably of sary toprovide ample facilities forlubrication, ferent diameters, in steps decrin fr m h .but again the necessity to gather the machinery middletowards each end, so that the various into close quarters makes itdiflicult to get at Parts a ed t y y e e y assembled the parts foroiling and greasing. thereon and removed therefrom.

Since failure of the boom hoist'would allow Beginning for convenience atthe left end of the boom to fall, it has been a common practice theshaft II as Seen n t a t (1 to give the boom hoist drum an irreversible3o p s s u iv ly a u al in the beari drive, not relying, on brakes tohold it against preferably provided with washers IE to take leftrunningout. Consequently a worm drive is used ward end thrust; a large drivinggear l5 keyed for the purpose, but since the worm shaft is at OtherwiseSuitably s u d p the a right angles to the worm wheel, such a driveroller bearing l6; heavy threads I! upon the cenrequires bevel 'or otherright angle change of tml Portion of the Shaft; another roller bearingdirection in the gear train from the principal 3; a f i n d brake diskkeyed Othershaftin to the worm wheel, or else places the wise suitably fboth axially a d c cu fe enboom hoist drum axis lengthwise instead oftially 0n t e s and fl el ya journal in the crosswise, necessitatingcarrying the line around bearing l3. The th e ed ction is pr fer bly aleader pulley. 40 integral with the shaft H, although it could be Myinvention is'for the purpose of providing Separately made a keyed 0 Oterwise fixed a boom hoist retaining the advantages of a Worm p thetdrive while avoiding its disadvantages, thus af- A boom hoist drum 20is carried in the manfording a compact assembly, fitting in with the nerof a nut upon the threads H, the drum beusual arrangements of themachinery, giving ing CorreSpOndinglY internally t ead d- T s largebearing and holding surfaces, not dependdrum 20 is supported on theshaft II by the ent upon a separate brake for its holding action, rollerbearings l6 and I8 recessed in the respeccapable of lowering the boomonly by driving tive ends of the drum. Both bearings, as shown thehoisting shaft in the opposite direction, with in Fig- 1, allow axialmovement of the drum.

the bearin surfaces all constantly lubricative 5 The right flange 2| ofthe drum is inset from and easily accessible for renewal of the lubritheend, le ving a Shank 22 to which a friction cant. all parts so arrangedthat repairs can be ring 23 i5 Suitably fastened, relatively movablereadily made when necessary. These features axially but not radially asy a key The are combined with a transverse location of the brake disk Hhas an inwardlye t s drum, conforming to that of the other drums, -verseface 25 positioned opposite the friction i k 23 but spaced therefrom.The face 25, ring, 23'

and flange 2| are all of about the same size and shape to receivesandwiched between them the inner webs 26 and 21 of two ratchet wheels23 and 23. The brake disk 13 also includes a; rim 30 surrounded by aband brake 3| of conventional' type, applied by a spring 32 and releasedby a cam 33.

-The ratchet wheels 28 and 2a are alike. Their rims are enlarged outsidetheir webs 26, 21 to ride on the peripheries of the members 2i, 23 andI3, and free rotation is possible except when axial movement of the drum'20 clamps the parts.

The twowheels areheld for rotation together,

. and their ratchet teeth are kept in alignment,'

' by studs 34, which allow axial movement.

necessary the studs may be secured to one of applied at the left end bya filling hole 40 through V the rim of the left flange ofdrum 23 and atthe right end by a filling hole 4| through the hub of brake disk l9. Itwill be observed that both filling holes are always accessible; 40cannot be blocked by a line wound on the drum. In this way both ends ofthe mechanism can be lubricated and'kept full of lubricant,- which willwork into the threads l1.

The operation of the mechanism will now be described, it beingunderstood that the hoist line 42 is secured to the drum, for example byclamp 43, and that turning the drum counterclockwise as seen in Fig. 2winds up the line to hoist the boom, while the unwinding movement isclockwise.

The operation is that when the shaft I l is stationary, gravity pull onthe line 42 by weight of the boom starts an unwinding action, turningthe drum 2B clockwise as seen in Fig. 2. The shaft ll cannot moveaxially, consequently the drum 20, acting as a rotating nut on astationary bolt, moves to the right until elements 2!, 26,13, 21 and 25are all frictionally clamped together, after which further unwinding isprevented by the pawl 35 holding the ratchets. Normally the shaft ii isheld stationary by its driving gear i5 and the train of drivingmechanism, but the brake 3| is added as an extra precaution.

To pay out the line 42 to lower the boom it is necessary to drive theshaft I i clockwise as shown sive momentary checks will not occur.

To hoist, the shaft is driven counterclockwise, the drum at first actingas a nut in tightening the friction system, and thereafter driving andclicking the ratchets over the pawl 35.

The foregoing description (with the drawings) of a preferred embodimentof my invention shows aform suitable for the boom hoist of a medium Vmovement of parts, and other factors, as will be apparent to thoseskilled in the art. quently itwill be understood that the foregoingConsedescription and accompanying drawings are by way of illustrationrather than of limitation, and that the invention is susceptible ofmodification in its details, all within the scope of the claims.

, I claim: Y

1.. A boom hoistmechanism comprising, a driving element operablyassociated with said shaft, a drum on said shaft, 9. hoist line wound onsaid drum, said line being secured to said drum, bearings between saiddrum and said shaft at opposite ends of said drumythreads connectingsaid drum'and said shaftintermediate said bearings, and a disk fastaxially and circumferentially on said shaft, releasable means forrestraining rotation of said'disk, a friction flange on one end of saiddrum, a friction'ring on the same end of said drum as said flangemovable axially but fast circumferentially with respect to said drum, afriction wheel rotatably mounted between said flange and said ring,another friction wheel rotatably mounted between said ring and saiddisk, ratchets on said friction wheels, and a pawl engaging saidratchets, the relative direction of said threads being such that turningsaid drum relatively to said shaft in the direction against said pawlmoves said friction elements together, while turning said shaftrelatively to said drum in the direction against said pawl moves saidfaces away from said disk.

2. A boom hoist mechanism for a materialhandling machine comprising incombination a shaft, a drum threaded thereon for limited independentendwise movement thereon, bearings between said drum and said shaft atopposite ends of said .drum upon which the drum rotates and slides, andoil seals between said drum and said shaft disposed outwardly of saidbearings, said drum being internally oil-tight whereby said seals andthe interior ofsaid drum define an oil chamber containing said threadsand said bearings.

3. A boom hoist mechanism for a materialhandling machine comprising incombination a haft, a drum threaded thereon for limited indep dentendwise movement thereon, bearings between said drum and said shaft atopposite ends of said drum upon which the drum rotates and slides, oilseals between said drum and said shaft disposed outwardly of saidbearings, said drum being internally oil-tight whereby said seals andthe interior of said drum define an oil chamber containing said threadsand said bearings; and lubricant supply passages opening into oppositeends of said chamber.

4. In a boom hoist mechanism of the character described, a shaft havinga screw threaded portion and bearing portions at opposite ends of thethreaded portion, a drum having an axial bore internally threaded toscrew on th threaded portion of the shaft and counterbores at oppositeends thereof, and anti-friction bearings for the drum mounted within thesaid counterbores, said drum being slidable axially on said bearings andsaid bearings being held against axial movement on the shaft.

5. In a boom hoist mechanism of the character described, a shaft havinga screw threaded portion and bearing portions at opposite ends of thethreaded portion, a drum having an axial bore internally threaded toscrew on the threaded portion of the shaft and counterbores at oppositeends thereof, and a roller hearing within each counterbore, each rollerbearing having an outer race ring fitting in the counterbore and aninner race ring fitting upon a bearing portion of the shaft, said innerrace ring being secured against axial movement on said shaft andsaidouter race ring being axially movable with respect to the inner racering.

6. In a boom hoist mechanism, a shaft having an enlarged central portionprovided with a screw thread, supportsin which said shaft is journaled,a winding drum having an axial bore provided with an internal threadengageable with the screw thread on the shaft, said drum havingcounterbores in its opposite ends, an antifriction bearing interposedbetween the drum and shaft in each of said counterbores, a gear fixed tothe shaft adjacent one endof the. drum and having a hub projecting intothe adjacent drum counterbore, a friction disk fixed to the shaftadjacent the opposite end of the drum and having a hub projecting intothe adjacent drum counterbore, sealing rings interposed between the endof the drum and said hubs, a friction wheel interposed between the drumand disk,

and means for restraining the rotation of said friction wheel.

' and oil sealing rings interposed between the drum and shaft withinsaid counterbores and outwardly of said hearings to retain lubricant inthe space within the drum in which the screw threads and bearings arelocated.

BERLIN S. FERGUSON.

